1. Field of the Invention
The present invention relates to a backpack work machine that a worker carries on the back for use. Specifically, the present invention relates to a backpack work machine having a motor mounted on a backpack frame that a worker carries on the back and a throttle lever provided to a fore end portion of an arm provided to a lower portion of the backpack frame, the throttle lever regulating output of the motor.
2. Description of Related Art
Japanese Patent Laid-Open Publication No. H10-299503 discloses a backpack blower having a blower unit that blows out air and is mounted on a backpack frame. In this backpack blower, the blower unit driven by an engine is mounted on the backpack frame that a worker carries on the back and air is discharged from a blower tube extending from a blowout duct of the blower unit. This backpack blower has an arm supported in a left side portion of the backpack frame, the arm being rotatable around a horizontal axis line of a left-right direction in a lower front portion. A throttle lever regulating output of the engine is provided to a fore end portion of the arm.
When using this backpack blower, a worker operates a grip handle of the blower tube with the right hand such that air discharged from a fore end opening of the blower tube is directed to fallen leaves scattered on the ground, and concurrently holds a grip in the fore end portion of the arm with the left hand and operates the throttle lever with the fingers so as to control an air volume discharged from the blower tube.
In the backpack blower of Japanese Patent Laid-Open Publication No. H10-299503, the arm is supported in the lower front portion of the left side portion of the backpack frame so as to be rotatable around the horizontal axis line of the left-right direction. When using the backpack blower, the worker rotates the arm from a position extending perpendicularly upward to a position extending forward, and holds the grip in the fore end portion of the arm in front of himself/herself with the left hand and operates the throttle lever with the fingers. In a state, however, where the arm is positioned in front of the body, the worker must hold the arm while closing off the left side of the body, thus getting tired from holding the arm in some cases. With the grip in the fore end portion of the arm positioned outward from the body, the worker can hold the grip of the arm in a position comfortable for the left hand without closing off the left side of the body. To this end, a coil spring is provided between the grip in the fore end portion and a pipe member in a base end portion of the arm. A portion where the coil spring is provided is freely deformable in a direction orthogonal to a longitudinal direction. Bending the coil spring allows the grip of the arm to be positioned outward from the body to some extent. However, the coil spring cannot be bent sufficiently to allow the left hand to be in a comfortable position.
In addition, the throttle lever in the fore end portion of the arm is a projection smaller than the grip in the fore end portion, the projection being rotated around the horizontal axis line of the left-right direction. Thus, the throttle lever is difficult to rotate. Furthermore, in a state of holding the grip of the arm, the worker can operate the throttle lever only with the thumb of the left hand. Thus, the worker tends to feel tired in the thumb of the left hand when performing the same operation for a long time.